This invention relates to a mechanical plug device to seal the interior of a pipeline. Particularly, this invention relates to a high pressure mechanical plug to internally seal and lock into pipelines having high internal pressures of up to approximately 1,000 p.s.i.
High pressure mechanical plug devices of this invention are useful to plug pipelines for testing and repair purposes. These high pressure mechanical plugs are particularly useful in such high pressure applications as in high pressure water pipelines, steam lines, petroleum and chemical lines as in commercial applications as in power plants. The mechanical plugs of this invention permit users to quickly and efficiently seal and plug high pressure pipelines such as steel pipes ranging in diameter from 1.5 to 18 inches. Additionally, the mechanical plug devices of the invention are constructed and arranged so that the internal pressure of the pipeline acts on the device structures to aid them in mechanically locking into the pipeline.
Although prior art mechanical plug devices have been proposed or developed for sealing pipelines, their respective structures have been limited to specific pipeline conditions. For example, U.S. Pat. No. 4,493,344 developed by the Applicants of this invention discloses a mechanical plug device for use in sealing relatively low pressure pipelines. Varying device structures have also been disclosed by others to seal pipelines having relatively low pressure environmental conditions.
The high pressure mechanical plug devices of this invention provide plug structures which function to both seal and mechanically seat or lock into pipelines having high internal pressures. And as far as is known, no such mechanical plug devices have heretofore been developed or proposed.